Map data distribution system and navigation apparatus

1. A map data distribution system comprising: a navigation apparatus comprising a distribution request transmitting section, a map data receiving section, an area information displaying section, and a distribution instruction transmitting section; and a map distribution server comprising a map data transmitting section, wherein the navigation apparatus is connected in communication with the map distribution server through a predetermined network; the distribution request transmitting section transmits a distribution request to the map distribution server, the distribution request including distribution conditions relating to the amount of map data to be distributed; the map data transmitting section transmits the map data satisfying the distribution conditions included in the distribution request; and the map data receiving section receives map data that satisfies the distribution conditions and that is sent in accordance with the distribution request; the map distribution server further comprising an area information transmitting section that, before the map data transmitting section transmits the map data, transmits area information showing a geographical area of the map data that is transmittable under the distribution conditions; the area information displaying section visually displays the geographical area of the map data that is receivable under the distribution conditions, in accordance with the area information transmitted from the man distribution server; and when an instruction to distribute the map data is given by a user after the display processing is performed by the area information displaying section, the distribution instruction transmitting section transmits the distribution instruction to the map distribution server, and the map data transmitting section transmits the map data after receiving the distribution instruction.

2. A map data distribution system according to claim 1 , wherein the area information displaying section displays map area information showing a geographical area corresponding to the map data that is transmittable in a single transmission operation under the distribution conditions, the map area information being superimposed on the map.

3. A map data distribution system according to claim 2 , wherein the map data transmitted from the map distribution server to the navigation apparatus comprises an update to map data held in the navigation apparatus.

4. A map data distribution system according to claim 3 , wherein the update is classified into different types depending on their uses, and the area information displaying section displays the map area information and the type of the update.

5. A map data distribution system according to claim 4 , wherein the type of the update is displayed using characters.

6. A map data distribution system according to claim 4 , wherein the area information displaying section displays each area corresponding to the map area information in a color in accordance with the type of the update.

7. A navigation apparatus comprising: a distribution request transmitting section; a map data receiving section; an area information displaying section; and a distribution instruction transmitting section; wherein the navigation apparatus is connected in communication with a map distribution server through a predetermined network and receives map data from the map distribution server; the distribution request transmitting section transmits a distribution request to the map distribution server, the distribution request including distribution conditions relating to the amount of the map data to be distributed; and the map data receiving section receives the map data that satisfies the distribution conditions and that is sent in accordance with the distribution request; wherein area information showing a geographical area of the map data that is transmittable under the distribution conditions is transmitted from the map distribution server prior to transmission of the map data, and the area information displaying section visually displays the geographical area of the map data that is receivable under the distribution conditions, in accordance with the area information; and when an instruction to distribute the map data is given by a user after the display processing is performed by the area information displaying section, the distribution instruction transmitting section transmits the distribution instruction to the map distribution server.

8. A navigation apparatus according to claim 7 , wherein the area information displaying section displays map area information showing a geographical area corresponding to the map data that is transmittable in a single transmission operation under the distribution conditions, the map area information being superimposed on the map.

9. A map data updating method for downloading map data from a map distribution server through a predetermined network and updating map data in a navigation apparatus, comprising: transmitting, by the navigation apparatus, a distribution request to the map distribution server, the distribution request including distribution conditions relating to the amount of map data to be distributed; transmitting, by the map distribution server, map data satisfying the distribution conditions included in the distribution request to the navigation apparatus; and receiving, by the navigation apparatus, the map data satisfying the distribution conditions transmitted from the map distribution server; wherein the map distribution server transmits area information to the navigation apparatus before transmitting the map data, the area information showing a geographical area of the map data that is transmittable under the distribution conditions; the navigation apparatus visually displays the geographical area of the man data that is receivable under the distribution conditions, in accordance with the area information transmitted from the man distribution server; and when an instruction to distribute the map data is given by a user after the display processing is performed, the navigation apparatus transmits the distribution instruction to the map distribution server, and the map distribution server transmits the map data after receiving the distribution instruction.

10. A map data updating method according to claim 9 , wherein the navigation apparatus displays map area information showing a geographical area corresponding to the map data that is transmittable in a single transmission operation under the distribution conditions, the map area information being superimposed on the map.

11. A map data updating method according to claim 10 , wherein the map data transmitted from the map distribution server comprises an update to map data held in the navigation apparatus.

12. A map data updating method according to claim 11 , wherein the navigation apparatus classifies the update into different types depending on their uses, and the navigation apparatus displays the map area information and the type of the update.

13. A map data updating method according to claim 12 , wherein the navigation apparatus displays the type of the update using characters.

14. A map data updating method according to claim 12 , wherein the navigation apparatus displays each area corresponding to the map area information in a color in accordance with the type of the update.